using System;
using System.Collections.Generic;
using System.Text;
using System.Reflection;
using System.Threading;
using System.Drawing;
using System.Linq;
using GrapeCity.Documents.Word;
using GrapeCity.Documents.Pdf;
using GrapeCity.Documents.Text;
using DocumentFormat.OpenXml.ExtendedProperties;

namespace DsWordWeb.Demos
{
    public static class Util
    {
        private static int s_gen = 0;
        private static DateTime s_fixedTime = new DateTime(1989, 6, 21, 1, 23, 45, DateTimeKind.Local);
        private static string[] s_words = new[]
        {
            "lorem", "ipsum", "dolor", "sit", "amet", "consectetur", "adipiscing", "elit", "mauris", "id", "volutpat",
            "tellus", "ullamcorper", "sem", "praesent", "et", "ante", "laoreet", "lobortis", "nunc", "congue",
            "nisi", "donec", "ac", "tempus", "sed", "feugiat", "pulvinar", "pharetra", "turpis", "nonummy",
            "at", "felis", "eget", "molestie", "euismod", "non", "aliquet", "diam", "proin", "mi", "nibh",
            "massa", "tincidunt", "ut", "dolore", "magna", "aliquam", "erat",
        };

        public static FontCollection FontCollection { get; set; }

        public static bool NoRandom { get; set; } = false;

        public static Random NewRandom()
        {
            if (NoRandom)
                return new Random(0);
            else
                return new Random((int)DateTime.Now.Ticks + Interlocked.Increment(ref s_gen));
        }

        public static DateTime TimeNow()
        {
            if (NoRandom)
                return s_fixedTime;
            else
                return DateTime.Now;
        }

        public static string LoremIpsumWord()
        {
            return s_words[NewRandom().Next(s_words.Length)];
        }

        public static List<string> LoremIpsum(
            int numParagraphs = 5,
            int minSentences = 5,
            int maxSentences = 10,
            int minWords = 5,
            int maxWords = 30)
        {
            List<string> result = new List<string>();
            for (int p = 0; p < numParagraphs; p++)
                result.Add(LoremIpsumPar(minSentences, maxSentences, minWords, maxWords));
            return result;
        }

        // https://stackoverflow.com/questions/4286487/is-there-any-lorem-ipsum-generator-in-c
        public static string LoremIpsumPar(
            int minSentences = 5,
            int maxSentences = 10,
            int minWords = 5,
            int maxWords = 30)
        {
            int commaMax = 10;
            var rnd = NewRandom();
            int numSentences = rnd.Next(maxSentences - minSentences) + minSentences + 1;
            int numWords = rnd.Next(maxWords - minWords) + minWords + 1;

            List<string> result = new List<string>();
            StringBuilder par = new StringBuilder();
            for (int s = 0; s < numSentences; s++)
            {
                for (int w = 0; w < numWords; w++)
                {
                    string word = LoremIpsumWord();
                    if (w == 0)
                    {
                        par.Append(char.ToUpper(word[0]));
                        par.Append(word.Substring(1));
                    }
                    else
                    {
                        if (rnd.Next(commaMax) == 0)
                            par.Append(',');
                        par.Append(' ');
                        par.Append(word);
                    }
                }
                par.Append(". ");
            }
            return par.ToString();
        }

        // https://stackoverflow.com/questions/273313/randomize-a-listt
        public static void Shuffle<T>(this IList<T> list)
        {
            var rnd = NewRandom();
            int n = list.Count;
            while (n > 1)
            {
                n--;
                int k = rnd.Next(n + 1);
                T value = list[k];
                list[k] = list[n];
                list[n] = value;
            }
        }

        /// <summary>
        /// Adds a note to the document - a text fragment on a yellow background.
        /// Used to insert meta info into sample documents.
        /// </summary>
        /// <param name="text">The text to draw.</param>
        /// <param name="page">The page to draw on.</param>
        /// <param name="bounds">The text bounds. If null, whole page with 1" margins all around is used.</param>
        /// <returns>The actual rectangle occupied by the note.</returns>
        public static RectangleF AddNote(string text, Page page, RectangleF? bounds = null)
        {
            var g = page.Graphics;
            var tl = g.CreateTextLayout();
            var pad = g.Resolution / 8f;
            tl.DefaultFormat.Font = StandardFonts.Helvetica;
            tl.DefaultFormat.FontSize = 12;
            if (!bounds.HasValue)
            {
                var margin = g.Resolution; // 1" margins by default
                bounds = new RectangleF(margin, margin, page.Size.Width - margin * 2, page.Size.Height - margin * 2);
            }
            tl.MaxWidth = bounds.Value.Width;
            tl.MaxHeight = bounds.Value.Height;
            tl.MarginLeft = tl.MarginRight = tl.MarginTop = tl.MarginBottom = pad;
            tl.Append(text);
            tl.PerformLayout(true);

            var rect = tl.ContentRectangle;
            rect.Offset(bounds.Value.Location);
            rect.Inflate(pad, pad);

            g.FillRectangle(rect, System.Drawing.Color.PaleGoldenrod);
            g.DrawRectangle(rect, System.Drawing.Color.DarkGoldenrod, 0.5f);
            g.DrawTextLayout(tl, bounds.Value.Location);

            return rect;
        }

        /// <summary>
        /// Set all page margins to 0.5".
        /// </summary>
        /// <param name="doc">The target document.</param>
        public static void SetNarrowMargins(GcWordDocument doc)
        {
            var margin = 36;
            doc.Body.Sections[0].PageSetup.Margin.Top = margin;
            doc.Body.Sections[0].PageSetup.Margin.Bottom = margin;
            doc.Body.Sections[0].PageSetup.Margin.Left = margin;
            doc.Body.Sections[0].PageSetup.Margin.Right = margin;
        }
    }
}